// Copyright 2006 Google Inc.


//


// Licensed under the Apache License, Version 2.0 (the "License");


// you may not use this file except in compliance with the License.


// You may obtain a copy of the License at


//


//   http://www.apache.org/licenses/LICENSE-2.0


//


// Unless required by applicable law or agreed to in writing, software


// distributed under the License is distributed on an "AS IS" BASIS,


// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.


// See the License for the specific language governing permissions and


// limitations under the License.








// Known Issues:


//


// * Patterns only support repeat.


// * Radial gradient are not implemented. The VML version of these look very


//   different from the canvas one.


// * Clipping paths are not implemented.


// * Coordsize. The width and height attribute have higher priority than the


//   width and height style values which isn't correct.


// * Painting mode isn't implemented.


// * Canvas width/height should is using content-box by default. IE in


//   Quirks mode will draw the canvas using border-box. Either change your


//   doctype to HTML5


//   (http://www.whatwg.org/specs/web-apps/current-work/#the-doctype)


//   or use Box Sizing Behavior from WebFX


//   (http://webfx.eae.net/dhtml/boxsizing/boxsizing.html)


// * Non uniform scaling does not correctly scale strokes.


// * Filling very large shapes (above 5000 points) is buggy.


// * Optimize. There is always room for speed improvements.





// Only add this code if we do not already have a canvas implementation


if (!document.createElement('canvas').getContext) {





(function() {





  // alias some functions to make (compiled) code shorter


  var m = Math;


  var mr = m.round;


  var ms = m.sin;


  var mc = m.cos;


  var abs = m.abs;


  var sqrt = m.sqrt;





  // this is used for sub pixel precision


  var Z = 10;


  var Z2 = Z / 2;





  /**


   * This funtion is assigned to the <canvas> elements as element.getContext().


   * @this {HTMLElement}


   * @return {CanvasRenderingContext2D_}


   */


  function getContext() {


    return this.context_ ||


        (this.context_ = new CanvasRenderingContext2D_(this));


  }





  var slice = Array.prototype.slice;





  /**


   * Binds a function to an object. The returned function will always use the


   * passed in {@code obj} as {@code this}.


   *


   * Example:


   *


   *   g = bind(f, obj, a, b)


   *   g(c, d) // will do f.call(obj, a, b, c, d)


   *


   * @param {Function} f The function to bind the object to


   * @param {Object} obj The object that should act as this when the function


   *     is called


   * @param {*} var_args Rest arguments that will be used as the initial


   *     arguments when the function is called


   * @return {Function} A new function that has bound this


   */


  function bind(f, obj, var_args) {


    var a = slice.call(arguments, 2);


    return function() {


      return f.apply(obj, a.concat(slice.call(arguments)));


    };


  }





  function encodeHtmlAttribute(s) {


    return String(s).replace(/&/g, '&amp;').replace(/"/g, '&quot;');


  }





  function addNamespacesAndStylesheet(doc) {


    // create xmlns


    if (!doc.namespaces['g_vml_']) {


      doc.namespaces.add('g_vml_', 'urn:schemas-microsoft-com:vml',


                         '#default#VML');





    }


    if (!doc.namespaces['g_o_']) {


      doc.namespaces.add('g_o_', 'urn:schemas-microsoft-com:office:office',


                         '#default#VML');


    }





    // Setup default CSS.  Only add one style sheet per document


    if (!doc.styleSheets['ex_canvas_']) {


      var ss = doc.createStyleSheet();


      ss.owningElement.id = 'ex_canvas_';


      ss.cssText = 'canvas{display:inline-block;overflow:hidden;' +


          // default size is 300x150 in Gecko and Opera


          'text-align:left;width:300px;height:150px}';


    }


  }





  // Add namespaces and stylesheet at startup.


  addNamespacesAndStylesheet(document);





  var G_vmlCanvasManager_ = {


    init: function(opt_doc) {


      if (/MSIE/.test(navigator.userAgent) && !window.opera) {


        var doc = opt_doc || document;


        // Create a dummy element so that IE will allow canvas elements to be


        // recognized.


        doc.createElement('canvas');


        doc.attachEvent('onreadystatechange', bind(this.init_, this, doc));


      }


    },





    init_: function(doc) {


      // find all canvas elements


      var els = doc.getElementsByTagName('canvas');


      for (var i = 0; i < els.length; i++) {


        this.initElement(els[i]);


      }


    },





    /**


     * Public initializes a canvas element so that it can be used as canvas


     * element from now on. This is called automatically before the page is


     * loaded but if you are creating elements using createElement you need to


     * make sure this is called on the element.


     * @param {HTMLElement} el The canvas element to initialize.


     * @return {HTMLElement} the element that was created.


     */


    initElement: function(el) {


      if (!el.getContext) {


        el.getContext = getContext;





        // Add namespaces and stylesheet to document of the element.


        addNamespacesAndStylesheet(el.ownerDocument);





        // Remove fallback content. There is no way to hide text nodes so we


        // just remove all childNodes. We could hide all elements and remove


        // text nodes but who really cares about the fallback content.


        el.innerHTML = '';





        // do not use inline function because that will leak memory


        el.attachEvent('onpropertychange', onPropertyChange);


        el.attachEvent('onresize', onResize);





        var attrs = el.attributes;


        if (attrs.width && attrs.width.specified) {


          // TODO: use runtimeStyle and coordsize


          // el.getContext().setWidth_(attrs.width.nodeValue);


          el.style.width = attrs.width.nodeValue + 'px';


        } else {


          el.width = el.clientWidth;


        }


        if (attrs.height && attrs.height.specified) {


          // TODO: use runtimeStyle and coordsize


          // el.getContext().setHeight_(attrs.height.nodeValue);


          el.style.height = attrs.height.nodeValue + 'px';


        } else {


          el.height = el.clientHeight;


        }


        //el.getContext().setCoordsize_()


      }


      return el;


    }


  };





  function onPropertyChange(e) {


    var el = e.srcElement;





    switch (e.propertyName) {


      case 'width':


        el.getContext().clearRect();


        el.style.width = el.attributes.width.nodeValue + 'px';


        // In IE8 this does not trigger onresize.


        el.firstChild.style.width =  el.clientWidth + 'px';


        break;


      case 'height':


        el.getContext().clearRect();


        el.style.height = el.attributes.height.nodeValue + 'px';


        el.firstChild.style.height = el.clientHeight + 'px';


        break;


    }


  }





  function onResize(e) {


    var el = e.srcElement;


    if (el.firstChild) {


      el.firstChild.style.width =  el.clientWidth + 'px';


      el.firstChild.style.height = el.clientHeight + 'px';


    }


  }





  G_vmlCanvasManager_.init();





  // precompute "00" to "FF"


  var decToHex = [];


  for (var i = 0; i < 16; i++) {


    for (var j = 0; j < 16; j++) {


      decToHex[i * 16 + j] = i.toString(16) + j.toString(16);


    }


  }





  function createMatrixIdentity() {


    return [


      [1, 0, 0],


      [0, 1, 0],


      [0, 0, 1]


    ];


  }





  function matrixMultiply(m1, m2) {


    var result = createMatrixIdentity();





    for (var x = 0; x < 3; x++) {


      for (var y = 0; y < 3; y++) {


        var sum = 0;





        for (var z = 0; z < 3; z++) {


          sum += m1[x][z] * m2[z][y];


        }





        result[x][y] = sum;


      }


    }


    return result;


  }





  function copyState(o1, o2) {


    o2.fillStyle     = o1.fillStyle;


    o2.lineCap       = o1.lineCap;


    o2.lineJoin      = o1.lineJoin;


    o2.lineWidth     = o1.lineWidth;


    o2.miterLimit    = o1.miterLimit;


    o2.shadowBlur    = o1.shadowBlur;


    o2.shadowColor   = o1.shadowColor;


    o2.shadowOffsetX = o1.shadowOffsetX;


    o2.shadowOffsetY = o1.shadowOffsetY;


    o2.strokeStyle   = o1.strokeStyle;


    o2.globalAlpha   = o1.globalAlpha;


    o2.font          = o1.font;


    o2.textAlign     = o1.textAlign;


    o2.textBaseline  = o1.textBaseline;


    o2.arcScaleX_    = o1.arcScaleX_;


    o2.arcScaleY_    = o1.arcScaleY_;


    o2.lineScale_    = o1.lineScale_;


  }





  var colorData = {


    aliceblue: '#F0F8FF',


    antiquewhite: '#FAEBD7',


    aquamarine: '#7FFFD4',


    azure: '#F0FFFF',


    beige: '#F5F5DC',


    bisque: '#FFE4C4',


    black: '#000000',


    blanchedalmond: '#FFEBCD',


    blueviolet: '#8A2BE2',


    brown: '#A52A2A',


    burlywood: '#DEB887',


    cadetblue: '#5F9EA0',


    chartreuse: '#7FFF00',


    chocolate: '#D2691E',


    coral: '#FF7F50',


    cornflowerblue: '#6495ED',


    cornsilk: '#FFF8DC',


    crimson: '#DC143C',


    cyan: '#00FFFF',


    darkblue: '#00008B',


    darkcyan: '#008B8B',


    darkgoldenrod: '#B8860B',


    darkgray: '#A9A9A9',


    darkgreen: '#006400',


    darkgrey: '#A9A9A9',


    darkkhaki: '#BDB76B',


    darkmagenta: '#8B008B',


    darkolivegreen: '#556B2F',


    darkorange: '#FF8C00',


    darkorchid: '#9932CC',


    darkred: '#8B0000',


    darksalmon: '#E9967A',


    darkseagreen: '#8FBC8F',


    darkslateblue: '#483D8B',


    darkslategray: '#2F4F4F',


    darkslategrey: '#2F4F4F',


    darkturquoise: '#00CED1',


    darkviolet: '#9400D3',


    deeppink: '#FF1493',


    deepskyblue: '#00BFFF',


    dimgray: '#696969',


    dimgrey: '#696969',


    dodgerblue: '#1E90FF',


    firebrick: '#B22222',


    floralwhite: '#FFFAF0',


    forestgreen: '#228B22',


    gainsboro: '#DCDCDC',


    ghostwhite: '#F8F8FF',


    gold: '#FFD700',


    goldenrod: '#DAA520',


    grey: '#808080',


    greenyellow: '#ADFF2F',


    honeydew: '#F0FFF0',


    hotpink: '#FF69B4',


    indianred: '#CD5C5C',


    indigo: '#4B0082',


    ivory: '#FFFFF0',


    khaki: '#F0E68C',


    lavender: '#E6E6FA',


    lavenderblush: '#FFF0F5',


    lawngreen: '#7CFC00',


    lemonchiffon: '#FFFACD',


    lightblue: '#ADD8E6',


    lightcoral: '#F08080',


    lightcyan: '#E0FFFF',


    lightgoldenrodyellow: '#FAFAD2',


    lightgreen: '#90EE90',


    lightgrey: '#D3D3D3',


    lightpink: '#FFB6C1',


    lightsalmon: '#FFA07A',


    lightseagreen: '#20B2AA',


    lightskyblue: '#87CEFA',


    lightslategray: '#778899',


    lightslategrey: '#778899',


    lightsteelblue: '#B0C4DE',


    lightyellow: '#FFFFE0',


    limegreen: '#32CD32',


    linen: '#FAF0E6',


    magenta: '#FF00FF',


    mediumaquamarine: '#66CDAA',


    mediumblue: '#0000CD',


    mediumorchid: '#BA55D3',


    mediumpurple: '#9370DB',


    mediumseagreen: '#3CB371',


    mediumslateblue: '#7B68EE',


    mediumspringgreen: '#00FA9A',


    mediumturquoise: '#48D1CC',


    mediumvioletred: '#C71585',


    midnightblue: '#191970',


    mintcream: '#F5FFFA',


    mistyrose: '#FFE4E1',


    moccasin: '#FFE4B5',


    navajowhite: '#FFDEAD',


    oldlace: '#FDF5E6',


    olivedrab: '#6B8E23',


    orange: '#FFA500',


    orangered: '#FF4500',


    orchid: '#DA70D6',


    palegoldenrod: '#EEE8AA',


    palegreen: '#98FB98',


    paleturquoise: '#AFEEEE',


    palevioletred: '#DB7093',


    papayawhip: '#FFEFD5',


    peachpuff: '#FFDAB9',


    peru: '#CD853F',


    pink: '#FFC0CB',


    plum: '#DDA0DD',


    powderblue: '#B0E0E6',


    rosybrown: '#BC8F8F',


    royalblue: '#4169E1',


    saddlebrown: '#8B4513',


    salmon: '#FA8072',


    sandybrown: '#F4A460',


    seagreen: '#2E8B57',


    seashell: '#FFF5EE',


    sienna: '#A0522D',


    skyblue: '#87CEEB',


    slateblue: '#6A5ACD',


    slategray: '#708090',


    slategrey: '#708090',


    snow: '#FFFAFA',


    springgreen: '#00FF7F',


    steelblue: '#4682B4',


    tan: '#D2B48C',


    thistle: '#D8BFD8',


    tomato: '#FF6347',


    turquoise: '#40E0D0',


    violet: '#EE82EE',


    wheat: '#F5DEB3',


    whitesmoke: '#F5F5F5',


    yellowgreen: '#9ACD32'


  };








  function getRgbHslContent(styleString) {


    var start = styleString.indexOf('(', 3);


    var end = styleString.indexOf(')', start + 1);


    var parts = styleString.substring(start + 1, end).split(',');


    // add alpha if needed


    if (parts.length == 4 && styleString.substr(3, 1) == 'a') {


      alpha = Number(parts[3]);


    } else {


      parts[3] = 1;


    }


    return parts;


  }





  function percent(s) {


    return parseFloat(s) / 100;


  }





  function clamp(v, min, max) {


    return Math.min(max, Math.max(min, v));


  }





  function hslToRgb(parts){


    var r, g, b;


    h = parseFloat(parts[0]) / 360 % 360;


    if (h < 0)


      h++;


    s = clamp(percent(parts[1]), 0, 1);


    l = clamp(percent(parts[2]), 0, 1);


    if (s == 0) {


      r = g = b = l; // achromatic


    } else {


      var q = l < 0.5 ? l * (1 + s) : l + s - l * s;


      var p = 2 * l - q;


      r = hueToRgb(p, q, h + 1 / 3);


      g = hueToRgb(p, q, h);


      b = hueToRgb(p, q, h - 1 / 3);


    }





    return '#' + decToHex[Math.floor(r * 255)] +


        decToHex[Math.floor(g * 255)] +


        decToHex[Math.floor(b * 255)];


  }





  function hueToRgb(m1, m2, h) {


    if (h < 0)


      h++;


    if (h > 1)


      h--;





    if (6 * h < 1)


      return m1 + (m2 - m1) * 6 * h;


    else if (2 * h < 1)


      return m2;


    else if (3 * h < 2)


      return m1 + (m2 - m1) * (2 / 3 - h) * 6;


    else


      return m1;


  }





  function processStyle(styleString) {


    var str, alpha = 1;





    styleString = String(styleString);


    if (styleString.charAt(0) == '#') {


      str = styleString;


    } else if (/^rgb/.test(styleString)) {


      var parts = getRgbHslContent(styleString);


      var str = '#', n;


      for (var i = 0; i < 3; i++) {


        if (parts[i].indexOf('%') != -1) {


          n = Math.floor(percent(parts[i]) * 255);


        } else {


          n = Number(parts[i]);


        }


        str += decToHex[clamp(n, 0, 255)];


      }


      alpha = parts[3];


    } else if (/^hsl/.test(styleString)) {


      var parts = getRgbHslContent(styleString);


      str = hslToRgb(parts);


      alpha = parts[3];


    } else {


      str = colorData[styleString] || styleString;


    }


    return {color: str, alpha: alpha};


  }





  var DEFAULT_STYLE = {


    style: 'normal',


    variant: 'normal',


    weight: 'normal',


    size: 10,


    family: 'sans-serif'


  };





  // Internal text style cache


  var fontStyleCache = {};





  function processFontStyle(styleString) {


    if (fontStyleCache[styleString]) {


      return fontStyleCache[styleString];


    }





    var el = document.createElement('div');


    var style = el.style;


    try {


      style.font = styleString;


    } catch (ex) {


      // Ignore failures to set to invalid font.


    }





    return fontStyleCache[styleString] = {


      style: style.fontStyle || DEFAULT_STYLE.style,


      variant: style.fontVariant || DEFAULT_STYLE.variant,


      weight: style.fontWeight || DEFAULT_STYLE.weight,


      size: style.fontSize || DEFAULT_STYLE.size,


      family: style.fontFamily || DEFAULT_STYLE.family


    };


  }





  function getComputedStyle(style, element) {


    var computedStyle = {};





    for (var p in style) {


      computedStyle[p] = style[p];


    }





    // Compute the size


    var canvasFontSize = parseFloat(element.currentStyle.fontSize),


        fontSize = parseFloat(style.size);





    if (typeof style.size == 'number') {


      computedStyle.size = style.size;


    } else if (style.size.indexOf('px') != -1) {


      computedStyle.size = fontSize;


    } else if (style.size.indexOf('em') != -1) {


      computedStyle.size = canvasFontSize * fontSize;


    } else if(style.size.indexOf('%') != -1) {


      computedStyle.size = (canvasFontSize / 100) * fontSize;


    } else if (style.size.indexOf('pt') != -1) {


      computedStyle.size = fontSize / .75;


    } else {


      computedStyle.size = canvasFontSize;


    }





    // Different scaling between normal text and VML text. This was found using


    // trial and error to get the same size as non VML text.


    computedStyle.size *= 0.981;





    return computedStyle;


  }





  function buildStyle(style) {


    return style.style + ' ' + style.variant + ' ' + style.weight + ' ' +


        style.size + 'px ' + style.family;


  }





  function processLineCap(lineCap) {


    switch (lineCap) {


      case 'butt':


        return 'flat';


      case 'round':


        return 'round';


      case 'square':


      default:


        return 'square';


    }


  }





  /**


   * This class implements CanvasRenderingContext2D interface as described by


   * the WHATWG.


   * @param {HTMLElement} surfaceElement The element that the 2D context should


   * be associated with


   */


  function CanvasRenderingContext2D_(surfaceElement) {


    this.m_ = createMatrixIdentity();





    this.mStack_ = [];


    this.aStack_ = [];


    this.currentPath_ = [];





    // Canvas context properties


    this.strokeStyle = '#000';


    this.fillStyle = '#000';





    this.lineWidth = 1;


    this.lineJoin = 'miter';


    this.lineCap = 'butt';


    this.miterLimit = Z * 1;


    this.globalAlpha = 1;


    this.font = '10px sans-serif';


    this.textAlign = 'left';


    this.textBaseline = 'alphabetic';


    this.canvas = surfaceElement;





    var el = surfaceElement.ownerDocument.createElement('div');


    el.style.width =  surfaceElement.clientWidth + 'px';


    el.style.height = surfaceElement.clientHeight + 'px';


    el.style.overflow = 'hidden';


    el.style.position = 'absolute';


    surfaceElement.appendChild(el);





    this.element_ = el;


    this.arcScaleX_ = 1;


    this.arcScaleY_ = 1;


    this.lineScale_ = 1;


  }





  var contextPrototype = CanvasRenderingContext2D_.prototype;


  contextPrototype.clearRect = function() {


    if (this.textMeasureEl_) {


      this.textMeasureEl_.removeNode(true);


      this.textMeasureEl_ = null;


    }


    this.element_.innerHTML = '';


  };





  contextPrototype.beginPath = function() {


    // TODO: Branch current matrix so that save/restore has no effect


    //       as per safari docs.


    this.currentPath_ = [];


  };





  contextPrototype.moveTo = function(aX, aY) {


    var p = this.getCoords_(aX, aY);


    this.currentPath_.push({type: 'moveTo', x: p.x, y: p.y});


    this.currentX_ = p.x;


    this.currentY_ = p.y;


  };





  contextPrototype.lineTo = function(aX, aY) {


    var p = this.getCoords_(aX, aY);


    this.currentPath_.push({type: 'lineTo', x: p.x, y: p.y});





    this.currentX_ = p.x;


    this.currentY_ = p.y;


  };





  contextPrototype.bezierCurveTo = function(aCP1x, aCP1y,


                                            aCP2x, aCP2y,


                                            aX, aY) {


    var p = this.getCoords_(aX, aY);


    var cp1 = this.getCoords_(aCP1x, aCP1y);


    var cp2 = this.getCoords_(aCP2x, aCP2y);


    bezierCurveTo(this, cp1, cp2, p);


  };





  // Helper function that takes the already fixed cordinates.


  function bezierCurveTo(self, cp1, cp2, p) {


    self.currentPath_.push({


      type: 'bezierCurveTo',


      cp1x: cp1.x,


      cp1y: cp1.y,


      cp2x: cp2.x,


      cp2y: cp2.y,


      x: p.x,


      y: p.y


    });


    self.currentX_ = p.x;


    self.currentY_ = p.y;


  }





  contextPrototype.quadraticCurveTo = function(aCPx, aCPy, aX, aY) {


    // the following is lifted almost directly from


    // http://developer.mozilla.org/en/docs/Canvas_tutorial:Drawing_shapes





    var cp = this.getCoords_(aCPx, aCPy);


    var p = this.getCoords_(aX, aY);





    var cp1 = {


      x: this.currentX_ + 2.0 / 3.0 * (cp.x - this.currentX_),


      y: this.currentY_ + 2.0 / 3.0 * (cp.y - this.currentY_)


    };


    var cp2 = {


      x: cp1.x + (p.x - this.currentX_) / 3.0,


      y: cp1.y + (p.y - this.currentY_) / 3.0


    };





    bezierCurveTo(this, cp1, cp2, p);


  };





  contextPrototype.arc = function(aX, aY, aRadius,


                                  aStartAngle, aEndAngle, aClockwise) {


    aRadius *= Z;


    var arcType = aClockwise ? 'at' : 'wa';





    var xStart = aX + mc(aStartAngle) * aRadius - Z2;


    var yStart = aY + ms(aStartAngle) * aRadius - Z2;





    var xEnd = aX + mc(aEndAngle) * aRadius - Z2;


    var yEnd = aY + ms(aEndAngle) * aRadius - Z2;





    // IE won't render arches drawn counter clockwise if xStart == xEnd.


    if (xStart == xEnd && !aClockwise) {


      xStart += 0.125; // Offset xStart by 1/80 of a pixel. Use something


                       // that can be represented in binary


    }





    var p = this.getCoords_(aX, aY);


    var pStart = this.getCoords_(xStart, yStart);


    var pEnd = this.getCoords_(xEnd, yEnd);





    this.currentPath_.push({type: arcType,


                           x: p.x,


                           y: p.y,


                           radius: aRadius,


                           xStart: pStart.x,


                           yStart: pStart.y,


                           xEnd: pEnd.x,


                           yEnd: pEnd.y});





  };





  contextPrototype.rect = function(aX, aY, aWidth, aHeight) {


    this.moveTo(aX, aY);


    this.lineTo(aX + aWidth, aY);


    this.lineTo(aX + aWidth, aY + aHeight);


    this.lineTo(aX, aY + aHeight);


    this.closePath();


  };





  contextPrototype.strokeRect = function(aX, aY, aWidth, aHeight) {


    var oldPath = this.currentPath_;


    this.beginPath();





    this.moveTo(aX, aY);


    this.lineTo(aX + aWidth, aY);


    this.lineTo(aX + aWidth, aY + aHeight);


    this.lineTo(aX, aY + aHeight);


    this.closePath();


    this.stroke();





    this.currentPath_ = oldPath;


  };





  contextPrototype.fillRect = function(aX, aY, aWidth, aHeight) {


    var oldPath = this.currentPath_;


    this.beginPath();





    this.moveTo(aX, aY);


    this.lineTo(aX + aWidth, aY);


    this.lineTo(aX + aWidth, aY + aHeight);


    this.lineTo(aX, aY + aHeight);


    this.closePath();


    this.fill();





    this.currentPath_ = oldPath;


  };





  contextPrototype.createLinearGradient = function(aX0, aY0, aX1, aY1) {


    var gradient = new CanvasGradient_('gradient');


    gradient.x0_ = aX0;


    gradient.y0_ = aY0;


    gradient.x1_ = aX1;


    gradient.y1_ = aY1;


    return gradient;


  };





  contextPrototype.createRadialGradient = function(aX0, aY0, aR0,


                                                   aX1, aY1, aR1) {


    var gradient = new CanvasGradient_('gradientradial');


    gradient.x0_ = aX0;


    gradient.y0_ = aY0;


    gradient.r0_ = aR0;


    gradient.x1_ = aX1;


    gradient.y1_ = aY1;


    gradient.r1_ = aR1;


    return gradient;


  };





  contextPrototype.drawImage = function(image, var_args) {


    var dx, dy, dw, dh, sx, sy, sw, sh;





    // to find the original width we overide the width and height


    var oldRuntimeWidth = image.runtimeStyle.width;


    var oldRuntimeHeight = image.runtimeStyle.height;


    image.runtimeStyle.width = 'auto';


    image.runtimeStyle.height = 'auto';





    // get the original size


    var w = image.width;


    var h = image.height;





    // and remove overides


    image.runtimeStyle.width = oldRuntimeWidth;


    image.runtimeStyle.height = oldRuntimeHeight;





    if (arguments.length == 3) {


      dx = arguments[1];


      dy = arguments[2];


      sx = sy = 0;


      sw = dw = w;


      sh = dh = h;


    } else if (arguments.length == 5) {


      dx = arguments[1];


      dy = arguments[2];


      dw = arguments[3];


      dh = arguments[4];


      sx = sy = 0;


      sw = w;


      sh = h;


    } else if (arguments.length == 9) {


      sx = arguments[1];


      sy = arguments[2];


      sw = arguments[3];


      sh = arguments[4];


      dx = arguments[5];


      dy = arguments[6];


      dw = arguments[7];


      dh = arguments[8];


    } else {


      throw Error('Invalid number of arguments');


    }





    var d = this.getCoords_(dx, dy);





    var w2 = sw / 2;


    var h2 = sh / 2;





    var vmlStr = [];





    var W = 10;


    var H = 10;





    // For some reason that I've now forgotten, using divs didn't work


    vmlStr.push(' <g_vml_:group',


                ' coordsize="', Z * W, ',', Z * H, '"',


                ' coordorigin="0,0"' ,


                ' style="width:', W, 'px;height:', H, 'px;position:absolute;');





    // If filters are necessary (rotation exists), create them


    // filters are bog-slow, so only create them if abbsolutely necessary


    // The following check doesn't account for skews (which don't exist


    // in the canvas spec (yet) anyway.





    if (this.m_[0][0] != 1 || this.m_[0][1] ||


        this.m_[1][1] != 1 || this.m_[1][0]) {


      var filter = [];





      // Note the 12/21 reversal


      filter.push('M11=', this.m_[0][0], ',',


                  'M12=', this.m_[1][0], ',',


                  'M21=', this.m_[0][1], ',',


                  'M22=', this.m_[1][1], ',',


                  'Dx=', mr(d.x / Z), ',',


                  'Dy=', mr(d.y / Z), '');





      // Bounding box calculation (need to minimize displayed area so that


      // filters don't waste time on unused pixels.


      var max = d;


      var c2 = this.getCoords_(dx + dw, dy);


      var c3 = this.getCoords_(dx, dy + dh);


      var c4 = this.getCoords_(dx + dw, dy + dh);





      max.x = m.max(max.x, c2.x, c3.x, c4.x);


      max.y = m.max(max.y, c2.y, c3.y, c4.y);





      vmlStr.push('padding:0 ', mr(max.x / Z), 'px ', mr(max.y / Z),


                  'px 0;filter:progid:DXImageTransform.Microsoft.Matrix(',


                  filter.join(''), ", sizingmethod='clip');");





    } else {


      vmlStr.push('top:', mr(d.y / Z), 'px;left:', mr(d.x / Z), 'px;');


    }





    vmlStr.push(' ">' ,


                '<g_vml_:image src="', image.src, '"',


                ' style="width:', Z * dw, 'px;',


                ' height:', Z * dh, 'px"',


                ' cropleft="', sx / w, '"',


                ' croptop="', sy / h, '"',


                ' cropright="', (w - sx - sw) / w, '"',


                ' cropbottom="', (h - sy - sh) / h, '"',


                ' />',


                '</g_vml_:group>');





    this.element_.insertAdjacentHTML('BeforeEnd', vmlStr.join(''));


  };





  contextPrototype.stroke = function(aFill) {


    var W = 10;


    var H = 10;


    // Divide the shape into chunks if it's too long because IE has a limit


    // somewhere for how long a VML shape can be. This simple division does


    // not work with fills, only strokes, unfortunately.


    var chunkSize = 5000;





    var min = {x: null, y: null};


    var max = {x: null, y: null};





    for (var j = 0; j < this.currentPath_.length; j += chunkSize) {


      var lineStr = [];


      var lineOpen = false;





      lineStr.push('<g_vml_:shape',


                   ' filled="', !!aFill, '"',


                   ' style="position:absolute;width:', W, 'px;height:', H, 'px;"',


                   ' coordorigin="0,0"',


                   ' coordsize="', Z * W, ',', Z * H, '"',


                   ' stroked="', !aFill, '"',


                   ' path="');





      var newSeq = false;





      for (var i = j; i < Math.min(j + chunkSize, this.currentPath_.length); i++) {


        if (i % chunkSize == 0 && i > 0) { // move into position for next chunk


          lineStr.push(' m ', mr(this.currentPath_[i-1].x), ',', mr(this.currentPath_[i-1].y));


        }





        var p = this.currentPath_[i];


        var c;





        switch (p.type) {


          case 'moveTo':


            c = p;


            lineStr.push(' m ', mr(p.x), ',', mr(p.y));


            break;


          case 'lineTo':


            lineStr.push(' l ', mr(p.x), ',', mr(p.y));


            break;


          case 'close':


            lineStr.push(' x ');


            p = null;


            break;


          case 'bezierCurveTo':


            lineStr.push(' c ',


                         mr(p.cp1x), ',', mr(p.cp1y), ',',


                         mr(p.cp2x), ',', mr(p.cp2y), ',',


                         mr(p.x), ',', mr(p.y));


            break;


          case 'at':


          case 'wa':


            lineStr.push(' ', p.type, ' ',


                         mr(p.x - this.arcScaleX_ * p.radius), ',',


                         mr(p.y - this.arcScaleY_ * p.radius), ' ',


                         mr(p.x + this.arcScaleX_ * p.radius), ',',


                         mr(p.y + this.arcScaleY_ * p.radius), ' ',


                         mr(p.xStart), ',', mr(p.yStart), ' ',


                         mr(p.xEnd), ',', mr(p.yEnd));


            break;


        }


  


  


        // TODO: Following is broken for curves due to


        //       move to proper paths.


  


        // Figure out dimensions so we can do gradient fills


        // properly


        if (p) {


          if (min.x == null || p.x < min.x) {


            min.x = p.x;


          }


          if (max.x == null || p.x > max.x) {


            max.x = p.x;


          }


          if (min.y == null || p.y < min.y) {


            min.y = p.y;


          }


          if (max.y == null || p.y > max.y) {


            max.y = p.y;


          }


        }


      }


      lineStr.push(' ">');


  


      if (!aFill) {


        appendStroke(this, lineStr);


      } else {


        appendFill(this, lineStr, min, max);


      }


  


      lineStr.push('</g_vml_:shape>');


  


      this.element_.insertAdjacentHTML('beforeEnd', lineStr.join(''));


    }


  };





  function appendStroke(ctx, lineStr) {


    var a = processStyle(ctx.strokeStyle);


    var color = a.color;


    var opacity = a.alpha * ctx.globalAlpha;


    var lineWidth = ctx.lineScale_ * ctx.lineWidth;





    // VML cannot correctly render a line if the width is less than 1px.


    // In that case, we dilute the color to make the line look thinner.


    if (lineWidth < 1) {


      opacity *= lineWidth;


    }





    lineStr.push(


      '<g_vml_:stroke',


      ' opacity="', opacity, '"',


      ' joinstyle="', ctx.lineJoin, '"',


      ' miterlimit="', ctx.miterLimit, '"',


      ' endcap="', processLineCap(ctx.lineCap), '"',


      ' weight="', lineWidth, 'px"',


      ' color="', color, '" />'


    );


  }





  function appendFill(ctx, lineStr, min, max) {


    var fillStyle = ctx.fillStyle;


    var arcScaleX = ctx.arcScaleX_;


    var arcScaleY = ctx.arcScaleY_;


    var width = max.x - min.x;


    var height = max.y - min.y;


    if (fillStyle instanceof CanvasGradient_) {


      // TODO: Gradients transformed with the transformation matrix.


      var angle = 0;


      var focus = {x: 0, y: 0};





      // additional offset


      var shift = 0;


      // scale factor for offset


      var expansion = 1;





      if (fillStyle.type_ == 'gradient') {


        var x0 = fillStyle.x0_ / arcScaleX;


        var y0 = fillStyle.y0_ / arcScaleY;


        var x1 = fillStyle.x1_ / arcScaleX;


        var y1 = fillStyle.y1_ / arcScaleY;


        var p0 = ctx.getCoords_(x0, y0);


        var p1 = ctx.getCoords_(x1, y1);


        var dx = p1.x - p0.x;


        var dy = p1.y - p0.y;


        angle = Math.atan2(dx, dy) * 180 / Math.PI;





        // The angle should be a non-negative number.


        if (angle < 0) {


          angle += 360;


        }





        // Very small angles produce an unexpected result because they are


        // converted to a scientific notation string.


        if (angle < 1e-6) {


          angle = 0;


        }


      } else {


        var p0 = ctx.getCoords_(fillStyle.x0_, fillStyle.y0_);


        focus = {


          x: (p0.x - min.x) / width,


          y: (p0.y - min.y) / height


        };





        width  /= arcScaleX * Z;


        height /= arcScaleY * Z;


        var dimension = m.max(width, height);


        shift = 2 * fillStyle.r0_ / dimension;


        expansion = 2 * fillStyle.r1_ / dimension - shift;


      }





      // We need to sort the color stops in ascending order by offset,


      // otherwise IE won't interpret it correctly.


      var stops = fillStyle.colors_;


      stops.sort(function(cs1, cs2) {


        return cs1.offset - cs2.offset;


      });





      var length = stops.length;


      var color1 = stops[0].color;


      var color2 = stops[length - 1].color;


      var opacity1 = stops[0].alpha * ctx.globalAlpha;


      var opacity2 = stops[length - 1].alpha * ctx.globalAlpha;





      var colors = [];


      for (var i = 0; i < length; i++) {


        var stop = stops[i];


        colors.push(stop.offset * expansion + shift + ' ' + stop.color);


      }





      // When colors attribute is used, the meanings of opacity and o:opacity2


      // are reversed.


      lineStr.push('<g_vml_:fill type="', fillStyle.type_, '"',


                   ' method="none" focus="100%"',


                   ' color="', color1, '"',


                   ' color2="', color2, '"',


                   ' colors="', colors.join(','), '"',


                   ' opacity="', opacity2, '"',


                   ' g_o_:opacity2="', opacity1, '"',


                   ' angle="', angle, '"',


                   ' focusposition="', focus.x, ',', focus.y, '" />');


    } else if (fillStyle instanceof CanvasPattern_) {


      if (width && height) {


        var deltaLeft = -min.x;


        var deltaTop = -min.y;


        lineStr.push('<g_vml_:fill',


                     ' position="',


                     deltaLeft / width * arcScaleX * arcScaleX, ',',


                     deltaTop / height * arcScaleY * arcScaleY, '"',


                     ' type="tile"',


                     // TODO: Figure out the correct size to fit the scale.


                     //' size="', w, 'px ', h, 'px"',


                     ' src="', fillStyle.src_, '" />');


       }


    } else {


      var a = processStyle(ctx.fillStyle);


      var color = a.color;


      var opacity = a.alpha * ctx.globalAlpha;


      lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity,


                   '" />');


    }


  }





  contextPrototype.fill = function() {


    this.stroke(true);


  };





  contextPrototype.closePath = function() {


    this.currentPath_.push({type: 'close'});


  };





  /**


   * @private


   */


  contextPrototype.getCoords_ = function(aX, aY) {


    var m = this.m_;


    return {


      x: Z * (aX * m[0][0] + aY * m[1][0] + m[2][0]) - Z2,


      y: Z * (aX * m[0][1] + aY * m[1][1] + m[2][1]) - Z2


    };


  };





  contextPrototype.save = function() {


    var o = {};


    copyState(this, o);


    this.aStack_.push(o);


    this.mStack_.push(this.m_);


    this.m_ = matrixMultiply(createMatrixIdentity(), this.m_);


  };





  contextPrototype.restore = function() {


    if (this.aStack_.length) {


      copyState(this.aStack_.pop(), this);


      this.m_ = this.mStack_.pop();


    }


  };





  function matrixIsFinite(m) {


    return isFinite(m[0][0]) && isFinite(m[0][1]) &&


        isFinite(m[1][0]) && isFinite(m[1][1]) &&


        isFinite(m[2][0]) && isFinite(m[2][1]);


  }





  function setM(ctx, m, updateLineScale) {


    if (!matrixIsFinite(m)) {


      return;


    }


    ctx.m_ = m;





    if (updateLineScale) {


      // Get the line scale.


      // Determinant of this.m_ means how much the area is enlarged by the


      // transformation. So its square root can be used as a scale factor


      // for width.


      var det = m[0][0] * m[1][1] - m[0][1] * m[1][0];


      ctx.lineScale_ = sqrt(abs(det));


    }


  }





  contextPrototype.translate = function(aX, aY) {


    var m1 = [


      [1,  0,  0],


      [0,  1,  0],


      [aX, aY, 1]


    ];





    setM(this, matrixMultiply(m1, this.m_), false);


  };





  contextPrototype.rotate = function(aRot) {


    var c = mc(aRot);


    var s = ms(aRot);





    var m1 = [


      [c,  s, 0],


      [-s, c, 0],


      [0,  0, 1]


    ];





    setM(this, matrixMultiply(m1, this.m_), false);


  };





  contextPrototype.scale = function(aX, aY) {


    this.arcScaleX_ *= aX;


    this.arcScaleY_ *= aY;


    var m1 = [


      [aX, 0,  0],


      [0,  aY, 0],


      [0,  0,  1]


    ];





    setM(this, matrixMultiply(m1, this.m_), true);


  };





  contextPrototype.transform = function(m11, m12, m21, m22, dx, dy) {


    var m1 = [


      [m11, m12, 0],


      [m21, m22, 0],


      [dx,  dy,  1]


    ];





    setM(this, matrixMultiply(m1, this.m_), true);


  };





  contextPrototype.setTransform = function(m11, m12, m21, m22, dx, dy) {


    var m = [


      [m11, m12, 0],


      [m21, m22, 0],


      [dx,  dy,  1]


    ];





    setM(this, m, true);


  };





  /**


   * The text drawing function.


   * The maxWidth argument isn't taken in account, since no browser supports


   * it yet.


   */


  contextPrototype.drawText_ = function(text, x, y, maxWidth, stroke) {


    var m = this.m_,


        delta = 1000,


        left = 0,


        right = delta,


        offset = {x: 0, y: 0},


        lineStr = [];





    var fontStyle = getComputedStyle(processFontStyle(this.font),


                                     this.element_);





    var fontStyleString = buildStyle(fontStyle);





    var elementStyle = this.element_.currentStyle;


    var textAlign = this.textAlign.toLowerCase();


    switch (textAlign) {


      case 'left':


      case 'center':


      case 'right':


        break;


      case 'end':


        textAlign = elementStyle.direction == 'ltr' ? 'right' : 'left';


        break;


      case 'start':


        textAlign = elementStyle.direction == 'rtl' ? 'right' : 'left';


        break;


      default:


        textAlign = 'left';


    }





    // 1.75 is an arbitrary number, as there is no info about the text baseline


    switch (this.textBaseline) {


      case 'hanging':


      case 'top':


        offset.y = fontStyle.size / 1.75;


        break;


      case 'middle':


        break;


      default:


      case null:


      case 'alphabetic':


      case 'ideographic':


      case 'bottom':


        offset.y = -fontStyle.size / 2.25;


        break;


    }





    switch(textAlign) {


      case 'right':


        left = delta;


        right = 0.05;


        break;


      case 'center':


        left = right = delta / 2;


        break;


    }





    var d = this.getCoords_(x + offset.x, y + offset.y);





    lineStr.push('<g_vml_:line from="', -left ,' 0" to="', right ,' 0.05" ',


                 ' coordsize="100 100" coordorigin="0 0"',


                 ' filled="', !stroke, '" stroked="', !!stroke,


                 '" style="position:absolute;width:1px;height:1px;">');





    if (stroke) {


      appendStroke(this, lineStr);


    } else {


      // TODO: Fix the min and max params.


      appendFill(this, lineStr, {x: -left, y: 0},


                 {x: right, y: fontStyle.size});


    }





    var skewM = m[0][0].toFixed(3) + ',' + m[1][0].toFixed(3) + ',' +


                m[0][1].toFixed(3) + ',' + m[1][1].toFixed(3) + ',0,0';





    var skewOffset = mr(d.x / Z) + ',' + mr(d.y / Z);





    lineStr.push('<g_vml_:skew on="t" matrix="', skewM ,'" ',


                 ' offset="', skewOffset, '" origin="', left ,' 0" />',


                 '<g_vml_:path textpathok="true" />',


                 '<g_vml_:textpath on="true" string="',


                 encodeHtmlAttribute(text),


                 '" style="v-text-align:', textAlign,


                 ';font:', encodeHtmlAttribute(fontStyleString),


                 '" /></g_vml_:line>');





    this.element_.insertAdjacentHTML('beforeEnd', lineStr.join(''));


  };





  contextPrototype.fillText = function(text, x, y, maxWidth) {


    this.drawText_(text, x, y, maxWidth, false);


  };





  contextPrototype.strokeText = function(text, x, y, maxWidth) {


    this.drawText_(text, x, y, maxWidth, true);


  };





  contextPrototype.measureText = function(text) {


    if (!this.textMeasureEl_) {


      var s = '<span style="position:absolute;' +


          'top:-20000px;left:0;padding:0;margin:0;border:none;' +


          'white-space:pre;"></span>';


      this.element_.insertAdjacentHTML('beforeEnd', s);


      this.textMeasureEl_ = this.element_.lastChild;


    }


    var doc = this.element_.ownerDocument;


    this.textMeasureEl_.innerHTML = '';


    this.textMeasureEl_.style.font = this.font;


    // Don't use innerHTML or innerText because they allow markup/whitespace.


    this.textMeasureEl_.appendChild(doc.createTextNode(text));


    return {width: this.textMeasureEl_.offsetWidth};


  };





  /******** STUBS ********/


  contextPrototype.clip = function() {


    // TODO: Implement


  };





  contextPrototype.arcTo = function() {


    // TODO: Implement


  };





  contextPrototype.createPattern = function(image, repetition) {


    return new CanvasPattern_(image, repetition);


  };





  // Gradient / Pattern Stubs


  function CanvasGradient_(aType) {


    this.type_ = aType;


    this.x0_ = 0;


    this.y0_ = 0;


    this.r0_ = 0;


    this.x1_ = 0;


    this.y1_ = 0;


    this.r1_ = 0;


    this.colors_ = [];


  }





  CanvasGradient_.prototype.addColorStop = function(aOffset, aColor) {


    aColor = processStyle(aColor);


    this.colors_.push({offset: aOffset,


                       color: aColor.color,


                       alpha: aColor.alpha});


  };





  function CanvasPattern_(image, repetition) {


    assertImageIsValid(image);


    switch (repetition) {


      case 'repeat':


      case null:


      case '':


        this.repetition_ = 'repeat';


        break


      case 'repeat-x':


      case 'repeat-y':


      case 'no-repeat':


        this.repetition_ = repetition;


        break;


      default:


        throwException('SYNTAX_ERR');


    }





    this.src_ = image.src;


    this.width_ = image.width;


    this.height_ = image.height;


  }





  function throwException(s) {


    throw new DOMException_(s);


  }





  function assertImageIsValid(img) {


    if (!img || img.nodeType != 1 || img.tagName != 'IMG') {


      throwException('TYPE_MISMATCH_ERR');


    }


    if (img.readyState != 'complete') {


      throwException('INVALID_STATE_ERR');


    }


  }





  function DOMException_(s) {


    this.code = this[s];


    this.message = s +': DOM Exception ' + this.code;


  }


  var p = DOMException_.prototype = new Error;


  p.INDEX_SIZE_ERR = 1;


  p.DOMSTRING_SIZE_ERR = 2;


  p.HIERARCHY_REQUEST_ERR = 3;


  p.WRONG_DOCUMENT_ERR = 4;


  p.INVALID_CHARACTER_ERR = 5;


  p.NO_DATA_ALLOWED_ERR = 6;


  p.NO_MODIFICATION_ALLOWED_ERR = 7;


  p.NOT_FOUND_ERR = 8;


  p.NOT_SUPPORTED_ERR = 9;


  p.INUSE_ATTRIBUTE_ERR = 10;


  p.INVALID_STATE_ERR = 11;


  p.SYNTAX_ERR = 12;


  p.INVALID_MODIFICATION_ERR = 13;


  p.NAMESPACE_ERR = 14;


  p.INVALID_ACCESS_ERR = 15;


  p.VALIDATION_ERR = 16;


  p.TYPE_MISMATCH_ERR = 17;





  // set up externs


  G_vmlCanvasManager = G_vmlCanvasManager_;


  CanvasRenderingContext2D = CanvasRenderingContext2D_;


  CanvasGradient = CanvasGradient_;


  CanvasPattern = CanvasPattern_;


  DOMException = DOMException_;


})();





} // if


